A comet from the deep space far beyond Pluto probably won’t smash into the Earth and obliterate all life, reassuring researchers said today. New calculations have determined that most extinction events that have occurred over our planet’s history probably weren’t caused by killer comet showers, which bodes well for the future, too. The findings are both welcome and well-timed since only last week an object dramatically smashed into Jupiter; many researchers believe the culprit was a comet.
In the new study, published in Science, researchers focused on long-period comets, which are among the wild cards in a thick deck of cosmic threats. In contrast with short-period comets, such as Comet Halley and Comet Tempel-Tuttle, long-period comets trace insanely eccentric orbits that range out beyond Neptune, Pluto and the Kuiper Belt to a little-understood region on the solar system’s edge known as the Oort Cloud [MSNBC]. The Oort cloud, which contains billions of small, icy objects, may extend from about 93 billion miles from the sun to as far as 9 trillion miles away.


Astronomers have spotted an icy object near Neptune that they say hails from the distant 
